I'm reasonably sure the issue you had was due to corruption of files during the download, there's no guarantee that with a zip file you would have different results. Unfortunately it happens on slow connections.

I know about intermediate mass black holes, but I figured that such black holes would not occur in simple binary systems like the examples I found; that only stellar black holes could be found under those circumstances.

I keep finding stars with masses hundreds or even thousands times that of the Sun. I don't think stars that massive should be even currently able to form. The most massive star known is over 300 solar masses.

The one found by steeljaw354 is definitely outside the red and brown dwarf range and firmly in the orange dwarf range.The planets in this system are also absurdly warm even accounting for tidal heating.